Saurodocus minimarenus, Yerman, Michelle N. & Krapp-Schickel, Traudl, 2008

Yerman, Michelle N. & Krapp-Schickel, Traudl, 2008, A new genus and two new species of Saurodocus (Crustacea: Amphipoda: Melitidae) from Lizard Island, Queensland, Australia, Zootaxa 1820, pp. 60-66 : 61-64

Saurodocus minimarenus sp. nov.

( Figs 1 , 2 )

Type material. Holotype: AM P77560, female, 1.2 mm, on slide, reef crest off Coconut Beach, Lizard Island, 14°41.037’S, 145°28.282’E, patches of coarse coral sand between reef, core, 2.6 m, M. Yerman, 23 February 2005, stn QLD 1620.

Etymology. A combination of the Latin words minimus, meaning small, and arena, meaning sand. These words are combined to give name to a ‘little sand dweller’.

Description of holotype. Head with anteroventral corner rounded; without notch or slit; eyes ovate to reniform. Antenna 1 longer than antenna 2, peduncle rather strong, peduncular article 1 longer than article 2, without robust setae along posterior margin; flagellum with 8 articles; accessory flagellum minute, with 2 articles. Antenna 2 peduncular article 2 cone gland not reaching to end of peduncular article 3; article 3 globular; article 4 subequal to longer than article 5; flagellum with 5 articles. Mandible palp inner margin of article 1 weakly produced distally, article 2 longer than article 3, article 3 longer than article 1, with 2 lateral setae, 3 smooth distal setae and many shorter setae along the surface. Maxilla 1 inner plate with 3 distal setae. Maxilla 2 inner plate with marginal setae, without oblique setal row. Maxilliped inner plate not reaching basis of outer plate, which is about the same length.

Pereon Gnathopod 1 coxa anteroventral corner not produced, anterior margin convex; carpus 0.6 x length of propodus, triangular, shorter than propodus; palm nearly transverse and defined by posterodistal corner. Gnathopod 2 propodus similar to gnathopod 1, but narrower and lacking palmar corner, anterior and posterior margins with setae; carpus triangular, shorter than propodus.

Pereopods 3–7 dactyli without anterodistal spine. Pereopods 5–7 slender, with few short setae, basis posterior margin smooth.

Pleon Pleonite 1 dorsally smooth. Pleonite 2 with dorsal spine. Pleonite 3 dorsally smooth. Epimeron 1 posteroventral corner with small acute or subacute spine. Epimeron 2 posteroventral corner acute. Epimeron 3 posteroventral margin distally with some small teeth. Urosomite 1 with long dorsal spine. Urosomite 2 posterior margin smooth. Urosomite 3 without dorsal setae. Uropod 1 peduncle longer than rami. Uropod 2 peduncle longer than rami. Uropod 3 rami 6.5 x longer than broad, distally acute or subacute, lanceolate, about double the length of the peduncle. Telson quadrangular, deeply cleft; longer than broad with 2 short, subapical robust setae on each lobe, no lateral setation.

Habitat. Living in coarse coral sand on coral reef at 2.6 m. Probably interstitial.

Distribution. Australia. Queensland: Lizard Island.

Remarks. Saurodocus minimarenus differs from S. hobbit in the following features: maxilla 2 does not have an oblique setal row (present in S. hobbit ); the gnathopod 2 propodus is shorter than that of S. hobbit ; the pleon bears dorsal spines (smooth in S. hobbit ); the posteroventral corner of epimeron 1 has a small acute spine (lacking in S. hobbit ), and the posteroventral corner of epimeron 3 is slightly serrated (smooth in S. hobbit ).

Figures

FIGURE 1. Saurodocus minimarenus sp. nov. holotype female, 1.2 mm, AM P 77560, Lizard Island.

FIGURE 2. Saurodocus minimarenus sp. nov. holotype female 1.2 mm, AM P 77560, Lizard Island.